1. Technical Field
The disclosure relates generally to light emitting devices, and more particularly to a light emitting diode (LED) chip and a method for manufacturing the same.
2. Description of Related Art
Nowadays light emitting diodes (LEDs) are used widely in various applications for illumination. There are two types of LED chips available in typical LEDs, a lateral LED chip and a vertical LED chip. The vertical LED chip generally includes a conductive substrate, an N-type semiconductor layer formed on the substrate, a light emitting layer formed on the N-type semiconductor layer, a p-type semiconductor layer formed on the light emitting layer, and a P-type electrode formed on the P-type semiconductor layer. In operation, current flows from the P-type electrode to the substrate, thereby activating the light emitting layer to emit light.
However, the P-type electrode has a smaller surface area less than that of the P-type semiconductor layer, and only covers a central area of the P-type semiconductor layer. The current flowing through the chip is prone to converge at a central portion of the chip corresponding to the P-type electrode. Thus, more current flows through the central portion of the chip than two lateral portions of the chip. As a result, the chip cannot emit light with uniform intensity due to uneven distribution of the current within the chip.
What is needed is an improved LED chip which can overcome the limitations described, and a method for manufacturing the LED chip.